The conventional toothbrushes are made by means of an automatic toothbrush manufacturing machine for mass production. The major function of said machine is to "automatically set bristles" in the "head" of an integrally moulded toothbrush body for cleaning the user's teeth in his mouth. However, when automatically setting bristles with the foregoing machine, a metal gasket together with a bundle of bristles will be set and inserted in many a bristles-setting groove in the said body, so that the bristles can be firmly set in the said groove and will not come off or become unserviceable when the user uses the toothbrush to clean his teeth. Therefore, disposing a metal gasket in the said groove is aimed at only fixing the bristles therein very firmly.
Since the metal .gasket (made of copper, nickle, chrome or alloy) disposed in the foregoing bristles-setting groove can be oxidized after it contacts hydrogen, oxygen or vapor in the air for a long time, and the residue of toothpaste containing fluorine, the tartar of tooth, and the moisture adhered to the toothbrush will gradually permeate to the bottom of bristles-setting groove to accelerate the oxidation and acidification of said metal gasket and to further generate undesirable chemicals and impuritiy which are detrimental to the health of human body. Once these chemicals and impurity during the action of brushing tooth, residually exist in the user's mouth, or in the course of drinking water, flow into the user's stomach and intestines, they will inevitably affect the health of the human body unfavorably. This is a major drawback of the conventional toothbrush with metal gasket fixed in the bristles-setting groove. In addition, the appropriate authorities in charge of health administration in some countries will also strictly control the unhealthful toothbrushes and bar sales or import of these poor toothbrushes in order to assure the health of their people. For instance, the FDA of the United States takes steps to strictly inspect and examine the toothbrushes with metal Gaskets. Obviously the problem of health and safety derived from toothbrush with metal gasket is a matter of concern.
In view of the drawback derived from the toothbrush with metal gasket which has to be improved without delay, the present inventor invented the present invention which is aimed at eliminating the drawback of conventional toothbrush to avoid the oxidation of metal Gasket from hurting the health of human body.